QbD-oriented development and validation of a bioanalytical method for nevirapine with enhanced liquid-liquid extraction and chromatographic separation.

The present studies describe the systematic quality by design (QbD)-oriented development and validation of a simple, rapid, sensitive and cost-effective reversed-phase HPLC bioanalytical method for nevirapine in rat plasma. Chromatographic separation was carried out on a C18 column using isocratic 68:9:23% v/v elution of methanol, acetonitrile and water (pH 3, adjusted by orthophosphoric acid) at a flow rate of 1.0 mL/min using UV detection at 230 nm. A Box-Behnken design was applied for chromatographic method optimization taking mobile phase ratio, pH and flow rate as the critical method parameters (CMPs) from screening studies. Peak area, retention time, theoretical plates and peak tailing were measured as the critical analytical attributes (CAAs). Further, the bioanalytical liquid-liquid extraction process was optimized using an optimal design by selecting extraction time, centrifugation speed and temperature as the CMPs for percentage recovery of nevirapine as the CAA. The search for an optimum chromatographic solution was conducted through numerical desirability function. Validation studies performed as per the US Food and Drug Administration requirements revealed results within the acceptance limit. In a nutshell, the studies successfully demonstrate the utility of analytical QbD approach for the rational development of a bioanalytical method with enhanced chromatographic separation and recovery of nevirapine in rat plasma. Copyright © 2015 John Wiley & Sons, Ltd.

QbD-Oriented Development and Characterization of Effervescent Floating-Bioadhesive Tablets of Cefuroxime Axetil.

The objective of the present studies was systematic development of floating-bioadhesive gastroretentive tablets of cefuroxime axetil employing rational blend of hydrophilic polymers for attaining controlled release drug delivery. As per the QbD-based approach, the patient-centric target product profile and quality attributes of tablet were earmarked, and preliminary studies were conducted for screening the suitability of type of polymers, polymer ratio, granulation technique, and granulation time for formulation of tablets. A face-centered cubic design (FCCD) was employed for optimization of the critical material attributes, i.e., concentration of release controlling polymers, PEO 303 and HPMC K100 LV CR, and evaluating in vitro buoyancy, drug release, and ex vivo mucoadhesion strength. The optimized formulation was embarked upon through numerical optimization, which yield excellent floatation characteristic with drug release control (i.e., T 60% > 6 h) and bioadhesion strength. Drug-excipient compatibility studies through FTIR and P-XRD revealed the absence of any interaction between the drug and polymers. In vivo evaluation of the gastroretentive characteristics through X-ray imaging and in vivo pharmacokinetic studies in rabbits revealed significant extension in the rate of drug absorption (i.e., T max, K a, and MRT) from the optimized tablet formulation as compared to the marketed formulation. Successful establishment of various levels of in vitro/in vivo correlations (IVIVC) substantiated high degree of prognostic ability of in vitro dissolution conditions in predicting the in vivo performance. In a nutshell, the studies demonstrate successful development of the once-a-day gastroretentive formulations of cefuroxime axetil with controlled drug release profile and improved compliance.

QbD-Enabled Development of Novel Stimuli-Responsive Gastroretentive Systems of Acyclovir for Improved Patient Compliance and Biopharmaceutical Performance.

The current studies entail systematic quality by design (QbD)-based development of stimuli-responsive gastroretentive drug delivery systems (GRDDS) of acyclovir using polysaccharide blends for attaining controlled drug release profile and improved patient compliance. The patient-centric quality target product profile was defined and critical quality attributes (CQAs) earmarked. Risk assessment studies, carried out through Ishikawa fish bone diagram and failure mode, effect, and criticality analysis, helped in identifying the plausible risks or failure modes affecting the quality attributes of the drug product. A face-centered cubic design was employed for systematic development and optimization of the concentration of sodium alginate (X 1) and gellan (X 2) as the critical material attributes (CMAs) in the stimuli-responsive formulations, which were evaluated for CQAs viz. viscosity, gel strength, onset of floatation, and drug release characteristics. Mathematical modeling was carried out for generation of design space, and optimum formulation was embarked upon, exhibiting formulation characteristics marked by excellent floatation and bioadhesion characteristics along with promising drug release control up to 24 h. Drug-excipient compatibility studies through FTIR and DSC revealed absence of any interaction(s) among the formulation excipients. In vivo pharmacokinetic studies in Wistar rats corroborated extension in the drug absorption profile from the optimized stimuli-responsive GR formulations vis-à-vis the marketed suspension (ZOVIRAX®). Establishment of in vitro/in vivo correlation (IVIVC) revealed a high degree of correlation between the in vitro and in vivo data. In a nutshell, the present investigations report the successful development of stimuli-responsive GRDDS of acyclovir, which can be applicable as a platform approach for other drugs too.

Nanocolloidal carriers of isotretinoin: antimicrobial activity against Propionibacterium acnes and dermatokinetic modeling.

Acne, a common skin disease in teenagers, is caused by Propionibacterium acnes (P. acnes). Isotretinoin (ITR) is though reported to have immense antiacne potential, yet there are hardly any reports vouching its antimicrobial activity. The present study, therefore, was undertaken to study the antimicrobial activity of ITR and evaluate the effect of its encasement in nanocarriers on its minimum inhibitory concentration (MIC). The nanocarriers were also evaluated for the skin transport characteristics. MICs of pure drug and entrapped drug in nanolipid carriers (ITR-NLCs) and in solid lipid nanoparticles (ITR-SLNs) were determined by broth dilution method against clindamycin phosphate as the reference antibiotic. It was observed that ITR possessed marked antimicrobial activity against anaerobic pathogen, P. acnes. Nanocarriers loaded with ITR, that is, SLNs and NLCs, enhanced the antimicrobial activity even at lower concentrations vis-à-vis the drug alone and improved drug transport potential vis-à-vis the commercial gel. The unique findings could be the result of effective adhesion of ITR-loaded nanocarriers to the bacterial membranes and release of drug directly to the target. Besides establishing ITR as an antimicrobial agent against acne-causing bacteria, the current work ratifies immense potential of nanocolloidal carriers like SLNs and NLCs to treat acne in a more efficient manner.

Long-chain triglycerides-based self-nanoemulsifying oily formulations (SNEOFs) of darunavir with improved lymphatic targeting potential.

The current studies entail systematic development of SNEOFs containing long-chain triglycerides for improving lymphatic targeting of darunavir for complete inhibition of HIV progression. As per QbD-oriented approach for formulation development, the QTPP was defined and CQAs were earmarked. Preformulation equilibrium solubility and phase diagram studies, and risk assessment through FMEA studies identified Lauroglycol 90, Tween 80 and Transcutol HP as the lipid, emulgent and cosolvent, respectively, for formulating SNEOFs of darunavir. Systematic optimisation of SNEOFs was conducted using IV-optimal mixture design, and the optimised formulation was chosen through numerical desirability function. Characterisation of optimised SNEOFs exhibited globule size of 50 nm, >85% drug release within 15 min and >75% permeation within 45 min. In vivo lymph cannulation and in situ intestinal perfusion studies indicated significant improvement in the drug absorption parameters from SNEOFs via intestinal lymphatic pathways, owing primarily to the presence of long-chain triglycerides. Also, in vivo pharmacokinetic studies in rat corroborated significant improvement in rate and extent of drug absorption into plasma vis-à-vis pure drug. In a nutshell, these studies indicate significant improvement in the biopharmaceutical attributes of a robust and stable SNEOFs formulation of darunavir for holistic management of viral loads in lymph and blood.

Stimuli-Responsive Systems with Diverse Drug Delivery and Biomedical Applications: Recent Updates and Mechanistic Pathways.

With the advent of "intelligent" polymeric systems, the use of stimuli-responsive in situ gelling systems has been revolutionized. These interesting polymers exist as free-flowing aqueous solutions before administration and undergo a phase transition to form a viscoelastic gel in a physiological environ through various stimuli such as temperature, pH, solvent, biochemical, magnetic, electric, ultrasound, and photo-polymerization. These smart polymers are endowed with numerous merits such as ease of administration, sustained release, reduced frequent administration with improved patient compliance, and targeted and spatial delivery of a drug with reduced frequency of side effects. Concerted efforts are being made to modify these polymers synthetically because they hold immense potential in various fields such as polymer chemistry, materials science, pharmaceutics, bioengineering medicine, and chemical engineering. In addition to novel drug delivery, these smart polymeric systems have exhibited tremendous applications in tissue engineering, regenerative biomedicine, molecular imprinting, cancer therapy, gene delivery, theranostic and other applications. The current review mainly focuses on the fundamental principles involved during in situ gelling, use of various "smart" drug-delivery formulation systems through diverse routes for their administration, as well as their well-documented biomedical applications. The pertinent literature, marketed formulations, and recent advances on these stimuli-responsive sol-gel-transforming systems are also discussed.

Systematic development of solid self-nanoemulsifying oily formulations (S-SNEOFs) for enhancing the oral bioavailability and intestinal lymphatic uptake of lopinavir.

The present studies entail the development of the systematically optimized solid self-nanoemulsifying oily formulations (S-SNEOFs) for enhancing the systemic bioavailability of lopinavir and targeting the same to the sanctuary site, i.e., lymphatic system for complete HIV inhibition. The patient-centric quality target product profile (QTPP) was defined and critical quality attributes (CQAs) earmarked. Risk assessment studies, carried out through failure mode and effect critically analysis (FMECA), helped in identifying the plausible risks or failure modes affecting the quality attributes of the drug product. As per the preliminary studies, viz solubility and phase titration studies, and factor screening studies, Maisine (i.e., lipid), Tween 80 (emulgent), Transcutol HP (i.e., cosolvent) were selected as the critical material attributes (CMAs) of the liquid SNEOFs (L-SNEOFs). D-optimal mixture design was employed for the optimization of aforesaid CMAs and evaluated for in vitro dissolution, globule size, ex vivo permeation studies as the critical quality attributes (CQAs). Optimal composition of CMAs, was embarked through numerical optimization and desirability function, exhibited excellent permeation and drug release characteristics besides possessing globule size in nano range, i.e., 53.16 nm. Further to increase the stability and drug loading, the OPT-L-SNEOFs were then adsorbed onto the porous carrier, i.e., Aeroperl, to prepare the OPT-SNEOF tablets which were finally compressed into the tablet employing MCC as the filler. The performance evaluation through in situ SPIP studies ascribed the significant enhancement in absorptivity parameters of both the SNEOFs vis-à-vis the pure drug. Also, chylomicron flow block SPIP studies revealed lymphatic uptake of lopinavir from the SNEOFs. Overall, in vivo pharmacokinetic studies in rats revealed significant improvement in the rate and extent of oral bioavailability of the SNEOFs compared to the pure drug. These studies further substantiate the intestinal lymphatic transport of lopinavir for the management of the sanctuary site HIV. In a nutshell, the SNEOFs offer a complete and holistic solution for the management of the viral loads in the lymph and blood.

QbD-enabled systematic development of gastroretentive multiple-unit microballoons of itopride hydrochloride.

The objectives of present studies were to develop the systematically optimized multiple-unit gastroretentive microballoons, i.e. hollow microspheres of itopride hydrochloride (ITH) employing quality by design (QbD)-based approach. Initially, the patient-centric QTPP and CQAs were earmarked, and preliminary studies were conducted to screen the suitable polymer, solvent, solvent ratio, pH and temperature conditions. Microspheres were prepared by non-aqueous solvent evaporation method employing Eudragit S-100. Risk assessment studies carried out by constructing Ishikawa cause-effect fish-bone diagram, and techniques like risk estimation matrix (REM) and failure mode effect analysis (FMEA) facilitated the selection of plausible factors affecting the drug product CQAs, i.e. percent yield, entrapment efficiency (EE) and percent buoyancy. A 3(3) Box-Behnken design (BBD) was employed for optimizing CMAs and CPPs selected during factor screening studies employing Taguchi design, i.e. drug-polymer ratio (X1), stirring temperature (X2) and stirring speed (X3). The hollow microspheres, as per BBD, were evaluated for EE, particle size and drug release characteristics. The optimum formulation was embarked upon using numerical desirability function yielding excellent floatation characteristics along with adequate drug release control. Drug-excipient compatibility studies employing FT-IR, DSC and powder XRD revealed absence of significant interaction among the formulation excipients. The SEM studies on the optimized formulation showed hollow and spherical nature of the prepared microspheres. In vivo X-ray imaging studies in rabbits confirmed the buoyant nature of the hollow microspheres for 8 h in the upper GI tract. In a nutshell, the current investigations report the successful development of gastroretentive floating microspheres for once-a-day administration of ITH.

Optimized nanoemulsifying systems with enhanced bioavailability of carvedilol.

The current studies entail a novel approach of formulating the solid self-nanoemulsifying drug delivery systems (S-SNEDDS) of carvedilol solely using rational blends of lipidic and emulsifying excipients without using equipment-intensive techniques and/or inert porous carriers. Delineating the nanoemulsion regions, the amounts of Capmul MCM (i.e., lipid) and Nikkol HCO 50 (i.e., emulgent) were selected as the critical factors for systematically formulating the optimized S-SNEDDS employing face centered cube design. The optimized formulation (mean globule size: 40.8 nm) indicated marked improvement in drug release profile vis-à-vis pure drug and marketed formulation. Augmentation in the values of C(max) (134.2%) and AUC (85.2%) indicated significant enhancement in the rate and extent of bioavailability by the S-SNEDDS formulation compared to pure drug. In situ SPIP studies ascribed the significant enhancement in absorptivity parameters of SNEDDS formulations to transport through the lymphatic system and reduced P-gp efflux. Successful establishment of various levels of in vitro/in vivo correlations (IVIVC's) substantiated the judicious choice of the in vitro dissolution milieu for simulating the in vivo conditions. The optimized formulation was found to be quite stable during six months of study period. The current investigations, therefore, report the successful development of systematically optimized S-SNEDDS with enhanced bioavailability potential of carvedilol.

Formulation development of gastroretentive tablets of lamivudine using the floating-bioadhesive potential of optimized polymer blends.

OBJECTIVES: The current studies entail successful formulation of optimized gastroretentive tablets of lamivudine using the floating-bioadhesive potential of carbomers and cellulosic polymers, and their subsequent in-vitro and in-vivo evaluation in animals and humans. METHODS: Effervescent floating-bioadhesive hydrophilic matrices were prepared and evaluated for in-vitro drug release, floatation and ex-vivo bioadhesive strength. The optimal composition of polymer blends was systematically chosen using central composite design and overlay plots. Pharmacokinetic studies were carried out in rabbits, and various levels of in-vitro/in-vivo correlation (IVIVC) were established. In-vivo gamma scintigraphic studies were performed in human volunteers using (99m) Tc to evaluate formulation retention in the gastric milieu. KEY FINDINGS: The optimized formulation exhibited excellent bioadhesive and floatational characteristics besides possessing adequate drug-release control and pharmacokinetic extension of plasma levels. The successful establishment of various levels of IVIVC substantiated the judicious choice of in-vitro dissolution media for simulating the in-vivo conditions. In-vivo gamma scintigraphic studies ratified the gastroretentive characteristics of the optimized formulation with a retention time of 5 h or more. CONCLUSIONS: Besides unravelling the polymer synergism, the study helped in developing an optimal once-a-day gastroretentive drug delivery system with improved bioavailability potential exhibiting excellent swelling, floating and bioadhesive characteristics.